what is the difference between $object::$variable and $object->variable

what is the difference between $object::$variable and $object->variable

what is the difference between $object::$variable and $object->variable
both of them can be used to achieve the same but creates difference when
the class member-variable is static as follows-
$object::$variable :- This syntax allows the static variable to be
achieved through the object
But
$object->variable :- This syntax does not allow the static variable to be
achieved through the object.
What is the semantic difference between the two?